Wet Equity

Like most runners, I'd rather look at lane lines on a track than in a pool. But 20 years ago, beset by recurring leg injuries, I took to the water in order to minimize the pounding. But I don't just count laps; I also "run." And what I've discovered is that when it comes to fitness, recovery, and feeling good, an hour in the pool is worth as much as an hour on the roads.

The resistance of water offers a cooling workout that taxes the body enough to maintain cardiovascular and muscular-skeletal fitness, while its buoyancy and zero-impact environment aids in recovery and injury prevention. A study published in the Journal of Sports Medicine and Physical Fitness compared groups that did pool running with those that did tread-mill running and found virtually equal VO2 max values (aerobic capacity). Another study by California State University Northridge found that when runners cooled down in water, they reported feeling more recovered compared with when they cooled down on a treadmill.

"Pool running sets up your hard days," says Michael Joyner, M.D., an exercise researcher at the Mayo Clinic, who swims and runs. He advises starting with one session per week of 30 to 45 minutes and increasing to two or more hour stints. "You leave the pool feeling refreshed, and you're ready to run hard the next day."

SWIM LAPSIf you haven't swum in a while, you may be surprised how tired you feel after swimming just a few laps. To help reduce fatigue and tap different muscle groups, alternate between freestyle, breaststroke, and backstroke.

Start out with about 10 laps (back and forth across the pool equals one lap), which is slightly more than a quartermile at a typical pool. Increase your time in the water and minimize fatigue (and boredom) by sandwiching pool-running in between sets of laps.

"RUN" IN WATERRunning against the water's resistance, in the deep end where you can't touch, provides many of the benefits of running on land. A flotation belt will help keep you upright and give you stability. Keeping your body erect, with a slight lean, and your gaze forward, run as you normally would on land with your hands pushing back the water. Don't expect to move forward much, says Craig Stuart, a pool-training instructor in Eugene, Oregon. Your leg action can vary: Do high knees and march in place, bend your knee slightly and move your legs as if you were cross-country skiing, or do a more long-striding leg extension.

To gauge your pace, compare how you feel while running in the water with how you feel running on the road (your perceived exertion). Or use your land times as a guide. If you typically do an interval workout of 8 x 400, take your time, say, one minute and 40 seconds, and run 8 x 1:40 at a hard effort in the pool.

STRETCH AND STRENGTHENThe pool is a perfect place to stretch out tight muscles because the water's buoyancy helps improve range of motion, says John Rembao, director of track-and-field operations at the University of California at Berkeley who has trained distance runners using pool work. In the deep end and without a belt, hang on to the edge with one hand, face the wall, and sweep your right leg from left to right and back again for 10 reps to stretch your glutes, adductors, and abductors. Repeat with your left leg. Next, stretch your quadriceps and hamstrings. Turn sideways to the edge, and hold it with one hand. Maintain a slight bend in your right knee, flex your foot so your toes are close to your shin, and sweep your right leg forward until it's roughly at a 90-degree angle to your body. (As your flexibility improves, your foot will break the surface of the water.) Sweep the leg backward while maintaining the bend in the knee. Do 10 reps then repeat with your left leg.

Water Works

The ideal pool workout should include 30 minutes of lap swimming and 30 minutes of pool running to ensure a full-body workout, says Michael Joyner, M.D., of the Mayo Clinic. For the running segment, perform one of the interval workouts below.